Thumbnail generation transform
Extract images from a video asset to generate thumbnails.
Thumbnails generation transforms are created using the transform endpoint from MK.IO API.
Thumbnail generation is only available for MP4 content and requires a server manifest (.ism) file provided as input to the job.
Depending on your use case, you can extract a single image, extract multiple images or generate a sprite image.
Thumbnails preset must use the #MediaKind.ThumbnailGeneratorPreset value for @data.type attribute.
Configuration parameters
The following table lists the configuration parameters for the thumbnail generation:
Parameter | Description |
|---|---|
| The output file format for the thumbnail. Can be either |
| The width of the output video for this layer. The value can be absolute (in pixels) or relative (in percentage). For example 50% means the output video has half as many pixels in width as the input. |
| The height of the output video for this layer. The value can be absolute (in pixels) or relative (in percentage). For example |
| The position in the input video from where to start generating thumbnails. The value can be in ISO8601 format with second-level precision (For example, PT05S to start at 5 seconds) or a relative value to asset duration (For example, |
| The position relative to start time in the input video at which to stop generating thumbnails. The value can be in ISO8601 format with second-level precision (For example, PT5M30S to stop at 5 minutes and 30 seconds from start time) or a relative value to the asset duration (For example, |
| The interval at which thumbnails are generated. The value can be in ISO8601 format with second-level precision (For example, |
| Used to create the output filename as |
| The compression quality of the JPEG images between 0 and 100. Default value is 70. |
| Multiple thumbnails can be aggregated in a sprite image. |
Transform examples
Below are sample transforms that illustrate how to use these parameters.
Once the transform is in place, it can be used to create a job on a given VOD asset.
Transform to generate a single thumbnail
Below is a sample transform that will generate a single PNG image 10s after the start of the content.
The image will be half the size of the top resolution of the input content.
curl --request PUT \
--url https://api.mk.io/api/ams/project_name/transforms/transform_name \
--header 'accept: application/json' \
--header 'content-type: application/json' \
--header 'Authorization: Bearer bearer-token' \
--data '
{
"properties": {
"outputs": [
{
"preset": {
"@odata.type": "#MediaKind.ThumbnailGeneratorPreset",
"thumbnails": [
{
"format": "Png",
"start": "PT10S",
"width": "50%",
"height": "50%"
}
]
}
}
]
}
}
'Transform to generate multiple thumbnails
The transform below generates one JPEG image every 30s during 80% of the input content.
The size of the image is defined by its width and the height will be calculated to maintain aspect ratio:
curl --request PUT \
--url https://api.mk.io/api/ams/project_name/transforms/transform_name \
--header 'accept: application/json' \
--header 'content-type: application/json' \
--header 'Authorization: Bearer bearer-token' \
--data '
{
"properties": {
"outputs": [
{
"preset": {
"@odata.type": "#MediaKind.ThumbnailGeneratorPreset",
"thumbnails": [
{
"format": "Jpeg",
"start": "10%",
"range": "90%",
"step": "PT30S",
"width": "480",
"quality": 70
}
]
}
}
]
}
}
'When multiple thumbnails are generated, MK.IO will also generate a VTT file to reference the associated timing.
Transform to generate a sprite file
MK.IO also gives the ability to generate a sprite file along with the associated VTT file.
The transform below generates one JPEG image every 1% of the content and organize them in a 10x10 sprite file.
curl --request PUT \
--url https://api.mk.io/api/ams/project_name/transforms/transform_name \
--header 'accept: application/json' \
--header 'content-type: application/json' \
--header 'Authorization: Bearer bearer-token' \
--data '
{
"properties": {
"outputs": [
{
"preset": {
"@odata.type": "#MediaKind.ThumbnailGeneratorPreset",
"thumbnails": [
{
"format": "Jpeg",
"start": "PT0S",
"range": "100%",
"step": "1%",
"width": "10%",
"height": "10%",
"spriteColumn": 10
}
]
}
}
]
}
}
'Sprite files can then be side loaded into players for scrubbing as describe in this article, Playout of a VOD asset with thumbnails seeking.
Combined generation of thumbnail and sprite files
MK.IO allows generating multiple thumbnail configuration in a single operation.
The transform below generates one JPEG image every 1% of the content and organize them in a 10x10 sprite file. It also generates a single PNG thumbnail with a fixed 1920x960 size.
curl --request PUT \
--url https://api.mk.io/api/ams/project_name/transforms/transform_name \
--header 'accept: application/json' \
--header 'content-type: application/json' \
--header 'Authorization: Bearer bearer-token' \
--data '
{
"properties": {
"outputs": [
{
"preset": {
"@odata.type": "#MediaKind.ThumbnailGeneratorPreset",
"thumbnails": [
{
"format": "Jpeg",
"start": "PT0S",
"range": "100%",
"step": "1%",
"width": "10%",
"height": "10%",
"spriteColumn": 10,
"quality": 90,
"label": "Sprite"
},
{
"format": "Png",
"start": "PT01S",
"width": "1920",
"height": "960",
"label": "Thumbnail"
}
]
}
}
]
}
}
'Updated about 2 months ago